1. Field of the Invention
The present invention relates to a connection method of a thermoplastic resin long body for interconnecting the end portions of a long body made of thermoplastic resin in which conductive unstretchable members are embedded within the thermoplastic resin, such as a moving handrail of a passenger conveyer or an escalator.
2. Background Art
A moving handrail of a passenger conveyer, an escalator, or the like includes, as chief members, a handrail main body normally made of rubber or a thermoplastic resin material, a large number of long slender copper cables (tensile bodies) embedded within the handrail main body along the longitudinal direction, and a canvas laminated to the under side of the handrail main body.
The copper cables function as a stretch preventing member that provides the handrail with a desired strength in the longitudinal direction while at the same time they are allowed to bend in the vertical direction to make the handrail movable about rollers and a drive mechanism. The canvas is bonded to the handrail in a T-shaped channel at the bottom of the handrail and is furnished with a function to reduce a frictional coefficient between the main body guide and the moving handrail.
The moving handrail is first formed as a thermoplastic resin long body and completed as a final product when it is processed in the form of a loop having a desired length by interconnecting the end portions of the long body. For example, JP-T-2000-507893 proposes to cut the end portions in alternating complex patterns with a cutting tool in order to obtain a sufficient bonding strength when the end portions of the long body are interconnected. The process to form the alternating patterns in the end portions, however, requires a cutting process to separate the handrail main body, a large number of copper cables, and the canvas as well as a cutting process to form the patterns.
The cutting processes using a cutting tool as above have a problem that it takes a long processing time to process thermoplastic resin widely and long (or deeply and long). In particular, the process to separate the handrail main body and a large number of copper cables requires a certain degree of processing accuracy. This raises a problem that the processing speed cannot be increased.
In addition, by merely butt-connecting the tips of the copper cables when interconnecting the end portions of the thermoplastic resin long body, in a case where the long body is used as a moving handrail, there arises a problem resulting from aging that the copper cables break through the thermoplastic resin and come out to the surface of the moving handrail.